topolvm-node

March 4, 2024 · View on GitHub

topolvm-node provides a CSI node service. It also works as a custom Kubernetes controller to implement dynamic volume provisioning.

CSI Node Features

topolvm-node implements following optional features:

Dynamic Volume Provisioning

topolvm-node watches LogicalVolume and creates or deletes LVM logical volumes by sending requests to LVMd.

If logicalvolume.status.volumeID is empty, it means that the logical volume correspond to LogicalVolume is not provisioned with LVMd. So in that case, topolvm-node sends CreateLV request to LVMd. If its response is succeeded, topolvm-node set logicalvolume.status.volumeID.

Finalize a Logical Volume

When a LogicalVolume resource is being deleted, topolvm-node sends a RemoveLV request to LVMd.

Prometheus Metrics

`topolvm_volumegroup_available_bytes`

topolvm_volumegroup_available_bytes is a Gauge that indicates the available free space in the LVM volume group in bytes.

Label	Description
`node`	The node resource name
`device_class`	The device class name.

`topolvm_volumegroup_size_bytes`

topolvm_volumegroup_size_bytes is a Gauge that indicates the size of the LVM volume group in bytes.

Label	Description
`node`	The node resource name
`device_class`	The device class name.

`topolvm_thinpool_data_percent`

topolvm_thinpool_data_percent is a Gauge that indicates the data space percentage used in the LVM thinpool.

Label	Description
`node`	The node resource name
`device_class`	The device class name.

`topolvm_thinpool_metadata_percent`

topolvm_thinpool_metadata_percent is a Gauge that indicates the metadata space percentage used of the LVM thinpool.

Label	Description
`node`	The node resource name
`device_class`	The device class name.

`topolvm_thinpool_size_bytes`

topolvm_thinpool_size_bytes is a Gauge that indicates the size of the LVM thin pool in bytes.

Label	Description
`node`	The node resource name
`device_class`	The device class name.

`topolvm_thinpool_overprovisioned_available`

topolvm_thinpool_overprovisioned_available is a Gauge that indicates the available overprovisioned size of the LVM thin pool in bytes.

Label	Description
`node`	The node resource name
`device_class`	The device class name.

Operations to Node Resources

topolvm-node adds capacity.topolvm.io/<device-class> annotations for each device-class and capacity.topolvm.io/00default annotation for the default device-class to the corresponding Node resource of the running node. The value is the free storage capacity reported by LVMd in bytes.

It also adds topolvm.io/node finalizer to the Node. The finalizer will be processed by topolvm-controller to clean up PVCs and associated Pods bound to the node.

Command-line Flags

Name	Type	Default	Description
`csi-socket`	string	`/run/topolvm/csi-topolvm.sock`	UNIX domain socket of `topolvm-node`.
`lvmd-socket`	string	`/run/topolvm/lvmd.sock`	UNIX domain socket of `LVMd` service.
`metrics-bind-address`	string	`:8080`	Bind address for the metrics endpoint.
`secure-metrics-server`	bool	`false`	Secures the metrics server.
`nodename`	string		`Node` resource name.

Environment Variables

NODE_NAME: Node resource name.

If both NODE_NAME and nodename flag are given, nodename flag is preceded.